The suspect in the killing of a veteran Metropolitan Police sergeant has been named as Louis De Zoysa.
The 23-year-old, who is thought to have shot himself, remains in a critical condition in hospital, and police said they have not yet been able to speak to him as part of the murder investigation.
It is claimed he was revived by doctors after ‘dying’ in hospital.
Sergeant Matiu (Matt) Ratana, 54, was fatally shot by a handcuffed suspect in the early hours of Friday at a police station in Croydon, south London.
It is said the officer, who was preparing for retirement, was planning to propose to girlfriend Sue Bushby, 44, after “six wonderful years” together. He is also survived by an adult son.
A man has been arrested on suspicion of supplying a firearm in connection with the murder investigation. He was arrested at around 2am of Sunday in Norwich, Norfolk.
Searches in Pollards Hill, Norbury, where the suspect was initially arrested by officers for possession of ammunition and possession of class B drugs on Friday, have finished, police said.
Other searches are taking place at the suspect’s home in Norbury in south London, and an address on Park Road, Banstead in Surrey, as well as forensic examinations on the custody suite where the incident unfolded in Croydon Custody Centre at about 2.15am on Friday.
The Independent Office for Police Conduct (IOPC), which attended the scene after the shooting, said the murder suspect had been taken into the building and sat in a holding area in the custody suite, then opened fire while still in handcuffs as officers prepared to search him with a metal detector.
He had earlier been arrested following a stop and search, then handcuffed behind his back before being taken to the station in a police vehicle.
No police firearms were fired in the incident, and the case is not being treated as terror-related.
The suspect, from Norbury, is said to have ‘died’ in hospital before being revived by medics.
Sergeant Ratana was originally from New Zealand and joined the Met in 1991. He was previously a protection officer to Princess Diana, the Queen Mother and ex-Prime Minister John Major.
The officer, who lived in Worthing, West Sussex, and was head coach for East Grinstead Rugby Club, was 300 yards from an IRA bomb that went off outside 10 Downing Street in 1992.